package com.wcj.test;

import com.wcj.linktable.ListNode;

public class 判断链表是否有环 {

    public boolean hasCycle(ListNode head) {
        ListNode slow = head;
        ListNode fast = head;
        while (fast != null && fast.next != null){
            slow = slow.next;
            fast = fast.next.next;
            if (slow == fast){
                return true;
            }
        }
        return false;
    }
}
